Liquid-tight connectors are commonly used in the electrical industry for providing a liquid-tight connection between electrical conduit and panels or junction boxes. These connectors are usually multi-piece devices in which a portion must be dismantled to fit the conduit into the fitting and then reassembled to secure the conduit. Most of these prior art fittings require the use of a hand tool to tighten a nut sufficiently to achieve a liquid-tight connection between the conduit and the connector. Most prior art liquid-tight connectors also require the tightening of a nut on the leading end of the fitting to achieve a liquid-tight connection between the fitting and the panel or junction box.
For example, U.S. Pat. No. 4,900,068 to Law, granted Feb. 13, 1990 (hereinafter the '068 patent) claims a liquid-tight connector that accepts a non-metallic conduit that is grasped by fingers on a clip grasping above an annular ring on a ferrule. To fit the conduit into the liquid-tight connector of the '068 patent, the installer must insert the conduit into the fitting, and then tighten a compression nut with a hand tool such as a wrench to close the fingers on the clip and thereby achieve a liquid-tight fit. The leading end of the fitting is threaded and must be inserted into the knock-out of a panel or box, a nut is screwed onto the threaded end, and then a hand tool is typically used to secure the fitting to the panel or box. A hand tool therefore is typically employed to achieve a secure liquid-tight fit on both the trailing end of the fitting, between the conduit and the fitting, and on the leading end of the fitting, between the fitting and the panel or box.
U.S. Pat. No. 5,072,072 granted to Bawa, et al., on Dec. 10, 1991 (hereinafter the '072 patent) attempts to improve upon the fitting provided in the '068 patent by providing a fitting that requires minimal torque on a gland nut to secure the conduit to the trailing end of the fitting. The gland nut must be removed from the connector body and then is inserted over an electrical conduit with the outer surface of the conduit being received through the centrally located bore of the gland nut. The conduit is then pushed onto a ferrule. Upon tightening of the gland nut on the connector body claimed by the '072 patent, the gland nut engages resilient fingers with minimal friction loss, thereby enhancing hand tightening or minimizing the torque required with a tightening tool. The '072 patent therefore requires the separate operation of tightening a nut either by hand or with a tightening tool. The leading end of the fitting in the '072 patent is typically threaded and requires the use of a nut and an O-ring to secure the fitting to the panel and achieve a liquid-tight fit.
Therefore, as described above, the disadvantages of existing art liquid-tight connectors for connecting conduit to panels include:
(a) The connector includes from two to five separate pieces, some of which must be partially or completely disassembled at the jobsite prior to insertion of the conduit and then reassembled after the conduit is inserted into the trailing end.
(b) Prior art liquid-tight connectors for conduit typically includes a compression, gland, or other nut that must be tightened by hand or by a tightening tool to achieve a liquid-tight connection on the trailing end between the conduit and the connector.
(c) The leading end of prior art liquid-tight connectors for electrical conduit typically require the use of a nut that must be tightened with a hand tool to achieve a liquid-tight fit between the connector and the panel.
(d) A separate sealing ring or O-ring is typically provided with prior art liquid-tight conduit connectors and must be assembled onto the leading end of the connector prior to insertion of the leading end into the knock-out on a panel or box.